Gianfranco Zola insists Mario Balotelli can be a "fantastic" player - if his talent can be successfully mastered.

Zola worked with the 22-year-old when in charge of Italy's under-21 team and admits he has an affection for the striker who has had a tempestuous time at Manchester City - culminating in this week's training ground bust-up with manager Roberto Mancini.

Balotelli came off the bench today and caused Zola's Watford side plenty of problems as City triumphed 3-0 in the FA Cup third round.

Afterwards Zola said: "I have an affection for him. I have worked with him for the under-21s and I do care about him and I do hope his potential is fulfilled.

"Even when he came on today you can see the potential in the man, and it's how to master that potential.

"I do hope he gets to that position as he will be a fantastic player. I am talking about what he can do to improve his situation but it's not down to me to say how.

"It's just that this is a young man with a lot of potential who can shine."

Carlos Tevez took the plaudits for City however with a dashing performance rounded off by a stunning free-kick. There were also goals for Gareth Barry and on his debut for Portuguese midfielder Marcos Lopes, who only turned 17 last week.

Watford's best chance came with score at 1-0 when Fernando Forestieri was through one-on-one but City's keeper Costel Pantilimon, in for the rested Joe Hart, pulled off an excellent diving save.

Zola added: "Maybe it would have been different if that had gone in. I admit they deserved to win but the scoreline was a bit unfair.

"We put a lot of faith in our young players and they did so well for us."

Zola made six changes but insisted most of those were down to injury and not because he was prioritising promotion to the top flight over the FA Cup.

"I believe it was the best team I could put out," he said.

Marcos Lopes is reputedly nicknamed 'Rony' after the Brazilian striker Ronaldinho - but City assistant manager David Platt brushed off any comparisons.

Platt said: "I hope not. His nickname is Marcos and he has played five minutes in an FA Cup tie and scored a goal. He should be proud of that and equally he should be ready to train tomorrow and he will be, with the under-21 team to play in their game on Monday.

"He's a good lad, he's got a very good temperament as well and he won't let that go to his head.

"He's got a big smile on his face at the moment. He came away with us in pre-season, did very, very well and has great lines as a footballer with great technical ability.

"He wants to hurt the opposition, wants to get in the box, and has been scoring goals like that for the under-21 team. He's got a good future ahead of him, certainly."

Platt added that the second goal just before the break had been the key to the match.

He said: "The second goal really knocked the stuffing out of them and we controlled the second half in the way we wanted.

"If we had conceded that one-on-one chance you never know what might have happened."